SUBJECT: A need for a standardised approach in biodiversity assessments
AUTHOR: Kajetan Perzanowski
DATE: 23rd April 2003

KEYWORDS: Biodiversity value, Natura 2000, management systems, anthropogenic pressure.

SUMMARY: Following a concept of biodiversity as an universal, special value of the biosphere it is necessary to elaborate a universal approach allowing to compare biodiversity retained in the same or various types of habitats being under different anthropogenic pressure.

To suggest the most important directions in biodiversity research, in order to improve their scientific quality, it is first necessary to clearly define the term itself. As it has been frequently pointed out, biodiversity is a convenient, even "politically correct" concept, understood and applied intuitively as having a universal, measurable value. Because of it usefulness, it is even occasionally possible to see a tendency towards its excessive use, e.g. when somebody speaks about biodiversity in a country.

It has to be accepted that although any diversity within biological systems can be generally referred to as biodiversity, for the purpose of comparative research, it is necessary to limit this concept to a framework can be measured in units reflecting a value of actual biodiversity level. It is fairly obvious that an approach to measure biodiversity as a number of biological categories (species, genomes or communities) per area unit, may serve only as quite self-evident comparisons, like saying that the level of biodiversity in the tundra is lower than in a rain forest. It is also clear that such a measure does not reflect a true value of biodiversity in different ecosystem types, not to mention its usefulness to compare a degree of biodiversity retention among regions being under various systems of land and resource management, or a level of biodiversity retained in anthropogenic habitats. Therefore, assuming that natural habitats (in practice almost gone by now in contemporary Europe) had an optimal level of biodiversity, there is a need to find a system allowing evaluating a relative value of biodiversity remaining in presently existing habitats.

Introduction of the Natura 2000 Network, as a universal system to maintain biodiversity of bio-geographical regions, may serve as a basis for comparison of actual biodiversity levels throughout Europe. For this purpose, for every habitat type recognised under the Natura 2000 system, it would be necessary to make an assessment of potential biodiversity level (under hypothetical natural conditions) in an agreed, standard way. Such a standard should be universal enough to be applied for the whole range of European habitats and not too complicated in order to be used for further routine monitoring.

The actual level of biodiversity measured in Natura 2000 sites would therefore be a fraction of the potential biodiversity level estimated for a relevant habitat type. That would allow for a direct comparison of retained biodiversity in the same habitat categories along the continent, but also to assess the level of retained biodiversity in various habitats being exposed to the same economic system, i.e. to compare a sensitivity of different habitats towards certain types of anthropogenic pressure. If extended over semi-natural and even anthropogenic habitats, this approach could as well serve to compare the level of biodiversity retained in such man-made systems as spruce plantations or potato fields in various European countries i.e. to measure the effects of different management practices upon the quality of human environment.


A contribution by:
Kajetan Perzanowski
The Carpathian Branch
International Centre for Ecology
Polish Academy of Sciences
38-700 Ustrzyki Dolne, Poland